i removed the lite-on then booted into bios.
ide's are set to autodetect.
then reinstalled lite-on as master on ide2 (without extra cdrom drive).
booted pc, and nothing, no bios, no post, just the same black screen.
the power light on the lite-on drive stays lit, HD spins up then does nothing, pressing the eject button on the drive doesnt eject the tray.
i then removed my new lite-on drive and replaced with a sammy304b combi(which wont burn anymore) and my pc booted fine.
then removed sammy304b and replaced with standard cdrom drive and my pc booted fine.
looks like the lite-on 24102b is knackered :(